Like many pp, I have a dd7 who was recently diagnosed with ASD (just ASD, but only ASD is diagnosed here -no AS, no HFA - she's demand avoidant, but fits all the criteria for PDA, PDA not an official diagnosis as it doesn't exist, maybe in DSM6 
Much more like a girl with HFA, did looks 'fine' at school (except she's not, school observation shows constant signs of anxiety). School picked up on nothing, saying she only showed signs of anxiety in my presence
.
At its very worst, did has self harmed (she was 6yo). Cutting herself with a paper clip, pizza wheel. She eye gouges, and as mentioned above, pulls out her hair. She did this in the school yard last week at drop off. She normally holds it in at school, but I see the potential for did to begin being able to lose the 'mask' at school.
For this reason along, I would pursue a diagnosis. I think I missed your ds age, but just because it may all be ok now, doesn't mean it will be in the future. Having a diagnosis has also allowed me to think about it more throughly and analytically. Up til now I've been focussed on getting dd's diagnosis (took just over 2 years), now I can focus on means urges to really help her and understand autism more as well